Amphibian aircraft pontoon



Dec. 3, 1935. A. P. DE Sufism; 2,023,312

AMPHIBIAN AIRCRAFT PONTOON Filed March 16, 1933 ATTORNEY Patented Dec.3, 1935 UNITED STATES 2,023,312 AMPHIBIAN AIRCRAFT PONTOON Alexander 1'.de Seversky, New York, N. Y., assignor to Seversky Aircraft Corporation,Farmingdale, N. Y., a corporation of Delaware Application March 1c,1933, Serial No. 661,014

9Claima. (cram-2) The present invention relates to amphibian aircraftand has for an object to provide an improved pontoon for such crait.

Amphibian .cra-it have been provided with pontoons having wheels whichfor landing on the ground are projected into ground engaging positionand for landing on water are retracted into wheel wells, in the pontoon.When the pontoon is moving rapidly through the water the well, if

opening below the water line, oflers a very considerable resistance tothe movement of the pontoon through the water by causing excessive eddycurrents and swirling of the water. In order to overcome this diflicultyit has been proposed to close the wheel well when the wheel is retractedbut'this arrangement oiiers certain mechanical diiilculties and from apractical point of view is not satisfactory.

The present invention aflords an arrangement for reducing the resistancecaused by the wheel well by providing a channel extending rearwardlyfrom the wheel well. The channel acts as a race way permitting a freeflow ofthe water rearwardly from wheel well and very much reduces the.

resistance to movement through the water.

The invention provides also an effective arrangement of skates or skidson the bottom of the pontoon for landing on or taking oil? from ice.

A novel shock absorbing auxiliary landing Wheel is also afforded as afeature of the invention.

The nature and objects of the invention will be better understood from aconsideration of a particular illustrative embodiment for the purpose ofwhich description reference should be had to the accompanying drawingforming a part hereof and in which:

Figure 1 is a perspective view of the bottom of a pontoon embodying theinvention,

Figure 2 is a central sectional view,

Figure 3 is a bottom plan view,

Figure 4 is a transverse sectional view of the pontoon taken on the line4-4 of Figure 2,

Figure 5 shows in side elevation the rudder and tail wheel with theshock absorbing connection to the body of the pontoon, and

Figure 6 is a detail view partly in section of the vertical ruddershaftand steering post.

The. pontoon shown for the purposes of illustratiori is in general or"the hollow sheet metal type, in which the aluminum sheathing 6 issupported by an interior frame work i, made up of angle bars and"F-bars. At the rear end a rudder f3 wither. auxiliary ground wheel 9 issecured by a shoclsabsorbing connection operable especially shorteningthe channel.

when landing on the ground. A wheel i is ad jus tably mounted in a wheelwell II andmay be projected to the position indicated at I2 on dottedlines in Figure 2, for landing on the ground or retracted to theposition indicated in full lines for landing on the water. In accordancewith the present invention the rear wall of the wheel well is cut away,to avoid the usual obstruction to the flow of water rearwardly. By thisarrangement the usual resistance to movement of the pontoon 10 due tothe eddying of the water in the wheel well is very much reduced. Theparticular shape of the bottom of the pontoon rearwardly of-this wellmay vary considerably. In the preferred arrangement illustrated in whichthe pontoon is stepped as indicated at I3, the bottom of the pontoon isrecessed to provide a channel I extending rearwardly out through thesteppedportion to permit a free flow of water from the wheel wellrearwardly in the raceway thus formed. The channel is shown as of thesame width as the wheel well but this width may be varied as conditionsrequire. The generally horizontal top of the inverted channel I4 ispreferably continued rearwardly in the same plane beyond the step andmerged into the contour of the bottom of the pontoon rear portion. Themerging, however, is preferably not smooth but a slight step is formedbetween the flat face I5 as continued rearwardly and the bottomof thepontoon. Such a step is clearly shown at IS in the drawing. It is notedalso that the step lies at an angle diagonally of the'length of thepontoon as the face I! forms a V.

The surface I5 is shown as'sloping slightly upwardly toward the rear.This slope is believed to be advantageous without unduly retarding freemovement and may even be increased considerably if desired even to thepoint of materially 40 When landing on or taking oft from the ground theload is taken by the wheel in projected into its lowermost position andby the auxiliary wheel S'carried by the rudder. The shockof engagementof the auxiliary wheel is resisted by a 4 shock absorbing connection ofthe rudder to the body or the pontoon. As shown in Fig. 5, a shockabsorber spring i8 is compressed between the bracket is on the rudderand the bracket 20 on the pontoon. The wheel 3 has a solid rubber tireto afiord a measure of resilience.

For landing on ice and more particularly for taking ofithereirom, it isdesirable to have a. skate structure on the landing gear. This is pro-Videci in the arrangement shown by applying to 5 the bottom of thepontoon steelor other hard metal strips. A strip 25 is applied to theforward portion of the pontoon along its center and strips 25 and 21 areapplied rearwardly of the wheel at the sides of the channel whichextends rearwardly from the wheel well.

These three strips are shaped to provide skate surfaces all, lying onone plane and which may by bearing on the ice effectively support thefull weight of the craft.. In order that the bearing surfaces may lie inthe same plane the rear end of the strip 25 is tapered as indicated at23 and the strips 26 and 21 are correspondingly shaped. A protectivemember 30 of similar metal is -also provided at the rear end of the stepIt and is so formed that in case of engagement with the ground or ice itwill also serve as a skid.

As indicated in Figs. and 6, the pivotal connection between the rudderand the bottom of the pontoon comprises telescoping sleeve members 32and 33. The inner member 32 is rigidly secured in a bracket 34 on thepontoon and slides in the'outer sleeve 33 which is rigidly connected tothe rudder at its upper end as indicated at 33. Upon upward movement ofthe rudder the sleeve 33 slides upwardly on the sleeve 32 and throughthe bearing 36 in the bracket 20 on the pontoon. In order to prevent toosudden return movement of the rudder 3 downwardly under the action ofthe spring II a dash-pot is provided within the sleeve 33. As shown, aplug 31 is rigidly secured to the top of the sleeve 32, preferablywelded thereto and this plug carries a leather washer 33. Above thiswasher a plug 33 is rigidly secured in the sleeve 33. Ordinarily an airdash-pot is satisfactory as distinguished from an oil dash-pot in whichthe oil is arranged to pass thmugh a small aperture in the plug 33 to aclosed chamber in the sleeve 33 above the plug. A cross-bar 40 issecured to the top of the sleeve 33 to provide suitable connection forsteering.

The foregoing particular description is illustrative merely and is notintended as defining thelimits of the invention.

I claim: a

1. A pontoon for amphibian aircraft having a wheel well, a wheelretractable into said wheel well and an inverted channel opening fromsaid wheel well and extending rearward along the bottom of the pontoonand terminating in a step toward the rear of the pontoon.

2. A pontoon for amphibian aircraft having a wheel well, a wheelretractable into said wheel well and an inverted channel opening fromsaid wheel well and extending rearward along the bottom of the pontoonand terminating in a step extending diagonally rearward along the bottomof the pontoon. 6

8. A pontoon for amphibian aircraft having a wheel well, a wheelretractable into said wheel well and an inverted channel opening fromsaid wheel well and extending rearward along the bottom of the pontoonand terminating in a step extending in a V rearwardly along the bottomof the pontoon, the bottom of the channel sloping downward toward therear of the pontoon.

4. -A pontoon for amphibian aircraft comprising a stepped pontoon bodyhaving a wheel well forward of the step and an inverted channel ofsubstantially the width of the wheel well extending rearward from thewheel well along the bottom of the pontoon.

' 5. A pontoon for amphibian aircraft comprising a stepped pontoon bodyhaving a wheel well forward of the step, a wheel adjustable in saidwell, the under-side of the pontoon being recessed rearward 6f the wheelwell to provide a raceway permitting free flow of water rearward fromthe well, substantially as described.

6.. A stepped pontoon for amphibian aircraft having a wheel well forwardof the step, a wheel adjustable in said wheel well, a channel extendingrearward from said wheel well to and beyond the-step and merging intothe pontoon body rearward of the step, substantially as described.

7. A pontoon for amphibian aircraft having a main float portion, arudder member pivoted to the rear end. of the main float portion andmovable vertically relative thereto, a resilient shock absorbing meansbetween the rudder member and the float portion to resiliently resistforces acting upwardly on the rudder and a dash pot yieldably resistingsudden downwardmovement of 40 V the rudder.

8. A pontoon for amphibian aircraft comprising a pontoon body having awheel well, a step rearwardly of the wheel well and a channel extendingrearwardiy from the wheel well through the step.

.9. A pontoon for amphibian aircraft comprising a pontoon body having awheel well and an inverted channel extending .rearwardly from the wheelwell and recessed into the bottom of the pontoon.

smxssnna P. or snvnaexr.

